Hundreds of cases of cancer of the lung, bladder, or skin could be avoided in New Hampshire by convincing private well users to test and treat their water to remove naturally occurring arsenic, according to a report prepared by Dartmouth College for the New Hampshire Department of Environmental Services (NHDES) and New Hampshire Department of Health and Human Services (NHDHHS). The study was conducted by a team of researchers from Dartmouth's Thayer School of Engineering, Geisel School of Medicine, and Superfund Research Program. Funding for the study came from the U.S. Centers for Disease Control and Prevention.

The study looked only at arsenic in private wells; water provided by public water systems is highly regulated under federal and state law. The study was prompted in part by the publication of statewide estimates of the occurrence of arsenic in private wells by the U.S. Geological Survey in 2012.

The report estimates that potentially avoidable cases of cancer from arsenic in private wells in the current New Hampshire population number from 450 to 600, based on federal government risk assessments published through 2001, but notes that a 2010 draft federal report, once finalized, would lead to an increased estimate. "We believe our estimate based on the currently available information is more likely to underestimate health effects in New Hampshire than overestimate them," noted Professor Mark Borsuk of the Thayer School, project leader for the Dartmouth study. "Over the last 25 years, the number of diseases associated with arsenic has increased, the parts of the body affected by arsenic-mediated diseases have increased, and estimates of what constitutes a safe long-term arsenic dose have decreased." ...

... The report goes on to recommend "intervention" measures aimed at increasing the number of New Hampshire well users who test their water and then use appropriate treatment to remove contaminants. The Dartmouth team will recruit local officials and health organizations to pilot those measures over the coming year.

Arsenic in private well water is a key concern of the New Hampshire Arsenic Consortium, which will meet on October 16 in Concord. More information about the arsenic consortium—a group of academic, government, and health organizations—is available from NHDES at 271-7061 and Dartmouth at 643-1868.

The report is available at http://des.nh.gov/organization/divisions/water/dwgb/well_testing/index.htm under "Hot Topics." For more information about the study, please contact Paul Susca, NHDES at (603) 271-7061 or Mark Borsuk, Dartmouth at (603) 646-9944.